Unexplainable weirdness

Has anyone ever had film not line up with the image on screen after exposure?

I am not talking about the "print" not lining up. I mean - if you place the film directly on the screen, the image on the screen is smaller than the image on the film.

Okay, here is where it gets even better. This is a 3 color job, and it happen for all 3 colors. The 3 films still line up perfectly, the 3 screens look to line up with each other, but the films do not line up with the screens.

We use high quality waterproof film. Expose our screens on a brand new Nuarc MSP3140. We dry our screens outside in sun.

We have imaged about 30 other screens this week, and none of them had this issue. The tension of the 3 that did this is relatively the same as the 30 that didn't.

That makes sense. The films do line up. We have certainly had printer feed issues before, but not this time. It seems that the most common answer is the sun. It is just strange to me because we put screens out to dry all the time, and this is the first (hopefully the last) time I have seen this. Thanks for the feedback everyone.